Ground Based Augmentation Systems (GBAS) for Global Navigation Satellite Systems (GNSS) broadcast one or more parameters that can be received by a GNSS receiver to correct for various errors in the satellite signals received. A scintillation threat occurs when ionospheric scintillation disturbances cause errors in the received satellite signals (Global Positioning System (GPS) signals). Ionospheric (iono) scintillation is a fluctuation of the GPS signal amplitude and/or phase, generated as the signal passes through localized anomalies in the total electron content (TEC) in the ionosphere. Ionospheric (iono) amplitude scintillation causes a rapid fluctuation of the GPS signal amplitude in signals passing through the ionosphere. These disturbances in the amplitude (signal strength) may affect the ability of the satellite systems Ground Based Augmentation System (GBAS) to detect out of tolerance precision approach information for an aircraft that is landing at an airport serviced by a ground station.
Since scintillation is not a rare occurrence, the ionosphere scintillation threatens satellite systems by generating “blinding” or false trip scenarios for some of the satellite fault monitors in the ground station sub-system. Additionally, ionosphere scintillation may cause an integrity monitor's underlying test statistic and its associated bounding sigma (σ) to be significantly different than expected and thereby unable to meet its required performance.